Brief speaking, the technology of a normal map is to convert the corresponding picture into small mirrors with different colors and angles.
Graphic design, photo editing and makeup, often add shadows to increase the stereoscopic. The technique is also used in 3D graphic rendering. This is today’s topic, the normal map.
The simplified principle is to flatten the height of the reflective surface. Then fine-tune the angle to simulate the original reflective surface. But it can only be like, can’t be the same.
Let’s explain it in plain language:
The normal map is to shoot a ray vertically from the center of each small mirror.
Record the intersection of the ray and the sphere with a radius of 1.
Or, we can imagine a rod is fixed in the center of the mirror.
$$ X = \frac{R-128}{127}, Y = \frac{G-128}{127}, Z = \frac{B-128}{127} $$
According to the previous rules, Let’s make a normal map by hand to experiment. F
Apply the normal map on the mirror surface for experimentation. Look at the city view, specular reflection angles are changed by the normal map.
Download a texture from polyHeaven. To briefly summarize the concepts explained earlier
The technology of a normal map is to convert the corresponding picture into small mirrors with different colors and angles. The texture map specifies the color of the small mirrors, The red, green, and blue channels of the normal map specify the XYZ coordinates of the mirror’s vertical emission.
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